Federal air marshals train to shoot accurately and to defend themselves in hand-to-hand combat against potential terrorists.
Robert Deutsch, USA TODAY

Transportation Security Administration K9 handler Tommy Karathomas and his explosive-detection dog Buddy perform a demonstration at LaGuardia Airport on January 20, 2016 in New York City.(Photo: Getty Images)

A Transportation Security Administration surveillance program for airline travelers is an important element to thwarting terrorists, despite concerns among civil-rights groups about who is chosen to be followed, the head of TSA said Wednesday.

But lawmakers and civil-rights groups criticized the program for potentially masking racial or religious discrimination. Part of identifying suspicious travelers relies on noticing behaviors such as fidgeting or having a penetrating stare, which government watchdogs and some lawmakers have criticized in the past as unreliable.

TSA Administrator David Pekoske told USA TODAY's editorial board that Quiet Skies has been in place for years and is a valuable piece of the air marshals' portfolio.

"In my view, it’s been very effective," Pekoske said. “I would say to the American public: Ordinary citizens don’t need to worry about Quiet Skies. They don’t. Actually ordinary citizens should be very happy that a program like Quiet Skies is in place because I think everybody expects us to do everything that we can do that protects the privacy and constitutional rights of our citizens to ensure that there is not an incident in an aircraft in flight."

But the Council on American-Islamic Relations, which has called on TSA to halt the program, announced Wednesday it would file a lawsuit in federal court challenging the program.

“The arbitrary surveillance of innocent people at airports guarantees that Muslim passengers will be disproportionately harassed by federal officials based on racial and religious profiling, with no benefit to the traveling public or to our nation’s security,” said Gadeir Abbas, senior litigation attorney for the group. “This is just the latest example of the federal government's counterproductive and misguided approach to aviation security.”

April Doss, a former associate general counsel for intelligence law at the National Security Agency, said key questions to ask about the TSA program include how people are chosen for surveillance and how the information gathered is used and distributed.

If information is kept for three months and compared with known terrorist threats, that could be more defensible than keeping information for five years and simply collecting data about common practices at the airport, she said.

“That starts to be very intrusive without being able to show that there is a good law enforcement or national security or homeland security reason for it,” said Doss, who is now a partner at Saul Ewing Arnstein & Lehr practicing cybersecurity and privacy law. “TSA needs to articulate how to choose who to surveil" to provide confidence that improper purposes aren't taking place against certain ethnic or religious affiliations.

The level of public surveillance allowed is a gray area of the law if the people aren’t searched, arrested or detained. Police used to routinely follow suspects around town. But the Supreme Court has ruled that modern technology such as tracking a car with a GPS device in a 2012 case or tracking someone by their phone’s location in a case this year might require a warrant.

“This is kind of an evolving area of the law,” Doss said.

The Quiet Skies program has air marshals follow travelers not suspected of a crime or on a terrorist watch list to gather more information about their movements, according to a TSA bulletin in March that the Globe obtained.

But some air marshals criticized the assignment as time-consuming and costly, diverting them from more vital work. Some of the travelers shadowed included a businesswoman who traveled through the Middle East, a Southwest Airlines flight attendant and another federal law enforcement officer, according to the Globe.

The teams document whether passengers fidget, use a computer, have a “jump” in their Adam’s apple or a “cold penetrating stare,” among other behaviors, according to the records reviewed by the Globe. Other suspicious behaviors include reversing direction in the airport, changing clothes or appearance in the airport or aboard a plane or observing a gate area from afar, according to the Globe.

When someone on the Quiet Skies list is selected for surveillance, a team of air marshals is placed on the person’s next flight. The team receives a file containing a photo and basic information — such as date and place of birth — about the target, according to agency documents.

Agency documents show there are about 40 to 50 Quiet Skies passengers on domestic flights each day, according to the Globe. On average, air marshals follow and surveil about 35 of them.

Pekoske said the number of air marshals and a detailed description of their duties are classified. But the Quiet Skies program is similar to any law enforcement surveillance around the world, he said. Pekoske compared it to police noticing a rise in burglaries in a neighborhood and patrolling more often until crime drops.

"They look at patterns of activity for people, and if a pattern fits a match that would create a concern, then they simply provide observation of those people for a period of time," Pekoske said. "When we have an air marshal that is observing the behavior of a passenger that we think presents a bit more risk than other passengers on board an aircraft, and they submit a report, that report is a TSA report."

Pekoske said the reports produced are TSA documents, and most are destroyed relatively quickly.

"Unless that report reveals something that requires further investigation, which in most cases it does not, then in most cases that is destroyed in a relatively quick period of time," Pekoske said.

In addition, Pekoske said the surveillance could eventually remove travelers from watch lists if the suspicion is unfounded.

"If they’re on a watch list for a reason, we have an obligation to validate that reason," Pekoske said. “If through observation we conclude that that person has no reason to be on that list, they come off that list. It’s a very small number of people."

TSA's behavior detection has been criticized in the past. The Government Accountability Office had reported in November 2013 that TSA’s behavior-detection program called Screening of Passengers by Observation Techniques was only slightly better than picking suspects by random chance. GAO reached the conclusion by reviewing 400 studies over 60 years that found people are only slightly better than chance at spotting deceptive behavior.

Behavior-detection training has since been merged into general TSA staffing.

“We’re in the process of training our entire workforce in general behavior-detection techniques," Pekoske said. "Our supervisors have much more advanced training in behavior detection. The supervisor will go over and either affirm or not what the officer observes."

Sen. Edward Markey, D-Mass., blasted the program as “the very definition of ‘Big Brother.’” He wrote TSA asking for answers about how people are selected for monitoring, how many have been followed, how many workers are involved and how many people have been arrested.

“This program raises serious privacy concerns, and depending on what criteria are being used for selecting individuals to surveil, including ethnicity, nationality, race, or religion, the program may be unconstitutional,” Markey said.

Hugh Handeyside, senior staff attorney with the American Civil Liberties Union’s national security project, said the group would file Freedom of Information Act requests to learn more about the program.

“Like the old, debunked ‘behavior detection’ program, Quiet Skies looks like the worst kind of waste,” Handeyside said, noting that even the Air Marshal Association criticized it. “From what we know about the TSA’s secret surveillance program, it’s a bad idea.”

Pekoske acknowledged the criticism from some air marshals and didn't expect unanimous support. But even while the number of air marshals is declining, Pekoske said Quiet Skies remains worthwhile.

“In any workforce, you’re going to have a percentage of people who don’t agree with what an agency wants them to do, or what any employer wants them to do," Pekoske said. "My job is to explain fully to my employees why we’re doing things that we do, and certainly to take their input seriously. But then it’s my job to agree or disagree. I disagree."